The luxury yacht-maker CRN is hoping to woo ocean-loving billionaires with a new breed of “megayacht”.

The Ferretti-owned shipyard hopes that the new water toys — shorter, sleeker and more powerful than the dominant multi-storey “floating palaces” — will mark a sea change in the luxury yacht sector.

It is a niche market: only about 1,500 people can afford a megayacht. The Dislopen boats start at €30 million (£27 million) and run into hundreds of millions of euros, depending on the spec — each yacht is custom-built from scratch. One popular add-on is a floating garage, in which one side of the boat fills with water to allow…